An organic electroluminescence (hereinafter, referred to as “organic EL”) display device includes a light emitting element provided in each of a plurality of pixels and displays an image by controlling light emission of each of the light emitting elements independently. The light emitting element has a structure in which a layer containing an organic EL material (hereinafter, also referred to as a “light emitting layer”) is interposed between a pair of electrodes, one of which is an anode electrode and the other of which is a cathode electrode. In such an organic EL display device, one of the electrodes is provided in each pixel as a pixel electrode, and the other electrode is provided in correspondence with the plurality of pixels as a common pixel electrode supplied with a common potential. The organic EL display device applies a potential of the pixel electrode in each pixel with respect to the potential of the common electrode, so as to control the light emission of each pixel.
Organic EL display devices, especially, flexible display devices including a thin substrate formed of a resin such as polyimide (PI) or the like have been actively developed. Such a flexible display device is produced as follows. A substrate including a support plate formed of glass or the like, a resin film formed of PI or the like provided thereon, and a thin film transistor circuit element and a light emitting element sequentially provided on the resin film is prepared (such a substrate is referred to as a “TFT-side substrate”). In the meantime, a substrate including another support plate, a resin film formed of PI or the like provided thereon, and color filters (CF) provided on the resin film is prepared (such a substrate is referred to as a “CF-side substrate”). These substrates are assembled together, and the two support plates are removed. The resultant assembly is divided into individual display devices. In this manner, flexible display devices including the thin PI resin substrates are produced.
Regarding such a flexible display device, the area size of a frame region outside a display area is desired to be decreased. In the vicinity of one side of the TFT-side substrate, namely, along one end of the TFT-side substrate, a plurality of terminals are provided. In order to decrease the area size of the frame region, it is conceivable to bend the end. It is conceivable to, for example, bend, by about 180 degrees, the end of the PI resin substrate along which the terminals are provided, so that the terminals are located on a rear surface of a panel.
For example, Japanese Laid-Open Patent Publication No. 2009-246820 discloses a display panel having a bent end portion. This publication discloses a mobile phone terminal solving the problems that, for example, with mere light-blocking printing, the entire surface except for the light irradiation area is not shielded against light and light leak occurs. The terminal includes a flat housing portion and a curved panel located on the flat housing portion. The curved panel includes a flat plate portion and a curved plate portion. A rear surface of the flat plate portion of the curved panel is provided with light-blocking printing. The flat housing portion and the flat plate portion of the curved panel are bonded together, with a light-blocking sheet member having a high light-blocking property being provided therebetween. With such a structure, colorful illumination is displayed on a rear panel of the mobile phone terminal. Unlike the present invention, the mobile phone terminal disclosed in this publication does not intend to increase the ratio of the display area size with respect to the sheet area size by bending the end of the panel, and the end portion is bent merely at about 90 degrees.
Japanese Laid-Open Patent Publication No. 2013-015835 discloses a flexible display panel including a flexible substrate that includes a first region, a second region extending from the first region and having a curved surface, and a third region bent with respect to the second region; a first display area located in the first region; a second display area located in the second region; non-display areas located outer to the first display area or the second display area, at least one of the non-display areas being located in the third region; and a sealing member sealing the first display area and the second display area. Unlike the present invention, the flexible display panel disclosed in this publication does not intend to increase the ratio of the display area size with respect to the sheet area size by bending the end of the panel, and the end portion is bent merely at about 90 degrees.